choose an image:
use as the bitmask you need js enabled
This tool masks an image's RGB bits. All images on a computer are stored in a way that, somehow, repersents a lot of numbers, all from 0 to 255. These numbers are grouped into threes (or fours): red, green, blue, and sometimes opacity. Red, green, and blue control the amount of light each "subpixel" in your screen emits, and you can see these subpixels with some magnifying glasses (usually ones that are far from ideal lenses), while alpha controls how much the image should layer when drawn ontop another image, although this alpha channel is commonly used for other things, especially in shader programs.